Everything is in place for the development of a supersonic business jet-except U.S. Federal Aviation Regulations.

Late last November, the national TV news shows all carried footage of a Concorde supersonic transport being barged slowly up New York's Hudson River to the Intrepid Sea-Air-Space Museum in Hudson River Park.

The image of the airplane, perched atop the barge like a wounded stork, still proudly holding its head high for all the media's cameras and crowds of onlookers, will be forever in my memory.

For many years I marveled as the Concordes swooped to a landing at Washington Dulles International Airport in northern Virginia. I was thrilled not only by the grace of their approach but by what they symbolized about the future of civil air transportation—a future defined by speed. With the retirement of the Concorde, was that future invalid? Did the Concorde's demise indicate that air travelers don't value speed and time?

This issue was addressed at a recent workshop on the future of supersonic flight sponsored by the Federal Aviation Administration. Richard Smith, executive vice president of Netjets, an organization that sells shares of business jets, recounted that fractional owners of aircraft sometimes find that their airplanes are not available when they want them because they are already in use by another owner. In such a situation, Netjets, like all fractional providers, will offer the owner an upgrade to another aircraft.

Smith noted that when owners of the fastest business jet available today, the Cessna Citation X, which cruises at Mach .92, need a substitute airplane, they are not interested in upgrading to a larger airplane; they want one equally fast. Their need is speed. There was no doubt in Smith's mind that a supersonic business jet would have buyers, and Netjets would surely be one of them.

Business jet manufacturers have been exploring the idea of a supersonic business jet for many years, but they realized that for customers to take full advantage of it, the craft would need to be able to fly supersonic over the world's landmasses, not just its oceans. The Concorde was not permitted to fly supersonic over the continental United States because federal regulations forbade it.

Currently, Part 91 of the Federal Aviation Regulations prohibits all civil aircraft operation at speeds greater than Mach 1 over the United States and imposes flight limitations to ensure that civil supersonic flights entering or leaving the country will not cause a sonic boom that could reach the surface of the landmass of the United States. Even if a supersonic aircraft slows to subsonic speed, its sonic boom plows on ahead of it, so this rule creates a buffer zone offshore.

In 1990, the Federal Aviation Administration proposed to amend the noise standards and operating rules for future civil supersonic airplanes. After analyzing the comments that this proposal received, the FAA determined that further investigation and research was necessary before a final rule could be developed. Specific noise standards have therefore not been established yet for future civil supersonic airplanes. The FAA anticipates that future proposed standards will require that an airplane's noise impact on a community not exceed that of a civil subsonic airplane certified to the most restrictive current noise levels. Is this feasible?

It may be. In 1999, NASA efforts to develop technologies for a supersonic large transport were terminated after all the manufacturers involved cited the high cost of development and what were anticipated to be stringent federal regulations regarding noise and emissions.